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			429 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			429 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C++
		
	
	
	
| // RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm -o - %s \
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| // RUN:   | FileCheck -check-prefix=CHECK-X86-64 %s
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| // RUN: %clang_cc1 -triple powerpc64-unknown-unknown -emit-llvm -o - %s \
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| // RUN:   | FileCheck -check-prefix=CHECK-PPC64 %s
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| //
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| // Tests for bitfield access patterns in C++ with special attention to
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| // conformance to C++11 memory model requirements.
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| 
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| namespace N0 {
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|   // Test basic bitfield layout access across interesting byte and word
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|   // boundaries on both little endian and big endian platforms.
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|   struct __attribute__((packed)) S {
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|     unsigned b00 : 14;
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|     unsigned b01 : 2;
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|     unsigned b20 : 6;
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|     unsigned b21 : 2;
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|     unsigned b30 : 30;
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|     unsigned b31 : 2;
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|     unsigned b70 : 6;
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|     unsigned b71 : 2;
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|   };
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|   unsigned read00(S* s) {
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|     // CHECK-X86-64: define i32 @_ZN2N06read00
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|     // CHECK-X86-64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-X86-64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-X86-64:   %[[and:.*]]   = and i64 %[[val]], 16383
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|     // CHECK-X86-64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-X86-64:                   ret i32 %[[trunc]]
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|     // CHECK-PPC64: define zeroext i32 @_ZN2N06read00
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|     // CHECK-PPC64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-PPC64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-PPC64:   %[[shr:.*]]   = lshr i64 %[[val]], 50
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|     // CHECK-PPC64:   %[[trunc:.*]] = trunc i64 %[[shr]] to i32
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|     // CHECK-PPC64:                   ret i32 %[[trunc]]
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|     return s->b00;
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|   }
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|   unsigned read01(S* s) {
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|     // CHECK-X86-64: define i32 @_ZN2N06read01
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|     // CHECK-X86-64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-X86-64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-X86-64:   %[[shr:.*]]   = lshr i64 %[[val]], 14
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|     // CHECK-X86-64:   %[[and:.*]]   = and i64 %[[shr]], 3
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|     // CHECK-X86-64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-X86-64:                   ret i32 %[[trunc]]
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|     // CHECK-PPC64: define zeroext i32 @_ZN2N06read01
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|     // CHECK-PPC64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-PPC64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-PPC64:   %[[shr:.*]]   = lshr i64 %[[val]], 48
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|     // CHECK-PPC64:   %[[and:.*]]   = and i64 %[[shr]], 3
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|     // CHECK-PPC64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-PPC64:                   ret i32 %[[trunc]]
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|     return s->b01;
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|   }
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|   unsigned read20(S* s) {
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|     // CHECK-X86-64: define i32 @_ZN2N06read20
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|     // CHECK-X86-64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-X86-64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-X86-64:   %[[shr:.*]]   = lshr i64 %[[val]], 16
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|     // CHECK-X86-64:   %[[and:.*]]   = and i64 %[[shr]], 63
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|     // CHECK-X86-64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-X86-64:                   ret i32 %[[trunc]]
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|     // CHECK-PPC64: define zeroext i32 @_ZN2N06read20
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|     // CHECK-PPC64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-PPC64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-PPC64:   %[[shr:.*]]   = lshr i64 %[[val]], 42
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|     // CHECK-PPC64:   %[[and:.*]]   = and i64 %[[shr]], 63
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|     // CHECK-PPC64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-PPC64:                   ret i32 %[[trunc]]
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|     return s->b20;
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|   }
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|   unsigned read21(S* s) {
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|     // CHECK-X86-64: define i32 @_ZN2N06read21
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|     // CHECK-X86-64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-X86-64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-X86-64:   %[[shr:.*]]   = lshr i64 %[[val]], 22
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|     // CHECK-X86-64:   %[[and:.*]]   = and i64 %[[shr]], 3
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|     // CHECK-X86-64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-X86-64:                   ret i32 %[[trunc]]
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|     // CHECK-PPC64: define zeroext i32 @_ZN2N06read21
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|     // CHECK-PPC64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-PPC64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-PPC64:   %[[shr:.*]]   = lshr i64 %[[val]], 40
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|     // CHECK-PPC64:   %[[and:.*]]   = and i64 %[[shr]], 3
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|     // CHECK-PPC64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-PPC64:                   ret i32 %[[trunc]]
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|     return s->b21;
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|   }
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|   unsigned read30(S* s) {
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|     // CHECK-X86-64: define i32 @_ZN2N06read30
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|     // CHECK-X86-64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-X86-64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-X86-64:   %[[shr:.*]]   = lshr i64 %[[val]], 24
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|     // CHECK-X86-64:   %[[and:.*]]   = and i64 %[[shr]], 1073741823
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|     // CHECK-X86-64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-X86-64:                   ret i32 %[[trunc]]
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|     // CHECK-PPC64: define zeroext i32 @_ZN2N06read30
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|     // CHECK-PPC64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-PPC64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-PPC64:   %[[shr:.*]]   = lshr i64 %[[val]], 10
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|     // CHECK-PPC64:   %[[and:.*]]   = and i64 %[[shr]], 1073741823
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|     // CHECK-PPC64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-PPC64:                   ret i32 %[[trunc]]
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|     return s->b30;
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|   }
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|   unsigned read31(S* s) {
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|     // CHECK-X86-64: define i32 @_ZN2N06read31
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|     // CHECK-X86-64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-X86-64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-X86-64:   %[[shr:.*]]   = lshr i64 %[[val]], 54
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|     // CHECK-X86-64:   %[[and:.*]]   = and i64 %[[shr]], 3
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|     // CHECK-X86-64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-X86-64:                   ret i32 %[[trunc]]
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|     // CHECK-PPC64: define zeroext i32 @_ZN2N06read31
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|     // CHECK-PPC64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-PPC64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-PPC64:   %[[shr:.*]]   = lshr i64 %[[val]], 8
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|     // CHECK-PPC64:   %[[and:.*]]   = and i64 %[[shr]], 3
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|     // CHECK-PPC64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-PPC64:                   ret i32 %[[trunc]]
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|     return s->b31;
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|   }
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|   unsigned read70(S* s) {
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|     // CHECK-X86-64: define i32 @_ZN2N06read70
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|     // CHECK-X86-64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-X86-64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-X86-64:   %[[shr:.*]]   = lshr i64 %[[val]], 56
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|     // CHECK-X86-64:   %[[and:.*]]   = and i64 %[[shr]], 63
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|     // CHECK-X86-64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-X86-64:                   ret i32 %[[trunc]]
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|     // CHECK-PPC64: define zeroext i32 @_ZN2N06read70
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|     // CHECK-PPC64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-PPC64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-PPC64:   %[[shr:.*]]   = lshr i64 %[[val]], 2
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|     // CHECK-PPC64:   %[[and:.*]]   = and i64 %[[shr]], 63
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|     // CHECK-PPC64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-PPC64:                   ret i32 %[[trunc]]
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|     return s->b70;
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|   }
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|   unsigned read71(S* s) {
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|     // CHECK-X86-64: define i32 @_ZN2N06read71
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|     // CHECK-X86-64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-X86-64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-X86-64:   %[[shr:.*]]   = lshr i64 %[[val]], 62
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|     // CHECK-X86-64:   %[[trunc:.*]] = trunc i64 %[[shr]] to i32
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|     // CHECK-X86-64:                   ret i32 %[[trunc]]
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|     // CHECK-PPC64: define zeroext i32 @_ZN2N06read71
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|     // CHECK-PPC64:   %[[ptr:.*]]   = bitcast %{{.*}}* %{{.*}} to i64*
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|     // CHECK-PPC64:   %[[val:.*]]   = load i64* %[[ptr]]
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|     // CHECK-PPC64:   %[[and:.*]]   = and i64 %[[val]], 3
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|     // CHECK-PPC64:   %[[trunc:.*]] = trunc i64 %[[and]] to i32
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|     // CHECK-PPC64:                   ret i32 %[[trunc]]
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|     return s->b71;
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|   }
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| }
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| 
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| namespace N1 {
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|   // Ensure that neither loads nor stores to bitfields are not widened into
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|   // other memory locations. (PR13691)
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|   //
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|   // NOTE: We could potentially widen loads based on their alignment if we are
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|   // comfortable requiring that subsequent memory locations within the
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|   // alignment-widened load are not volatile.
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|   struct S {
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|     char a;
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|     unsigned b : 1;
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|     char c;
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|   };
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|   unsigned read(S* s) {
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|     // CHECK-X86-64: define i32 @_ZN2N14read
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|     // CHECK-X86-64:   %[[ptr:.*]] = getelementptr inbounds %{{.*}}* %{{.*}}, i32 0, i32 1
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|     // CHECK-X86-64:   %[[val:.*]] = load i8* %[[ptr]]
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|     // CHECK-X86-64:   %[[and:.*]] = and i8 %[[val]], 1
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|     // CHECK-X86-64:   %[[ext:.*]] = zext i8 %[[and]] to i32
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|     // CHECK-X86-64:                 ret i32 %[[ext]]
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|     // CHECK-PPC64: define zeroext i32 @_ZN2N14read
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|     // CHECK-PPC64:   %[[ptr:.*]] = getelementptr inbounds %{{.*}}* %{{.*}}, i32 0, i32 1
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|     // CHECK-PPC64:   %[[val:.*]] = load i8* %[[ptr]]
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|     // CHECK-PPC64:   %[[shr:.*]] = lshr i8 %[[val]], 7
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|     // CHECK-PPC64:   %[[ext:.*]] = zext i8 %[[shr]] to i32
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|     // CHECK-PPC64:                 ret i32 %[[ext]]
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|     return s->b;
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|   }
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|   void write(S* s, unsigned x) {
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|     // CHECK-X86-64: define void @_ZN2N15write
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|     // CHECK-X86-64:   %[[ptr:.*]]     = getelementptr inbounds %{{.*}}* %{{.*}}, i32 0, i32 1
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|     // CHECK-X86-64:   %[[x_trunc:.*]] = trunc i32 %{{.*}} to i8
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|     // CHECK-X86-64:   %[[old:.*]]     = load i8* %[[ptr]]
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|     // CHECK-X86-64:   %[[x_and:.*]]   = and i8 %[[x_trunc]], 1
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|     // CHECK-X86-64:   %[[old_and:.*]] = and i8 %[[old]], -2
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|     // CHECK-X86-64:   %[[new:.*]]     = or i8 %[[old_and]], %[[x_and]]
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|     // CHECK-X86-64:                     store i8 %[[new]], i8* %[[ptr]]
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|     // CHECK-PPC64: define void @_ZN2N15write
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|     // CHECK-PPC64:   %[[ptr:.*]]     = getelementptr inbounds %{{.*}}* %{{.*}}, i32 0, i32 1
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|     // CHECK-PPC64:   %[[x_trunc:.*]] = trunc i32 %{{.*}} to i8
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|     // CHECK-PPC64:   %[[old:.*]]     = load i8* %[[ptr]]
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|     // CHECK-PPC64:   %[[x_and:.*]]   = and i8 %[[x_trunc]], 1
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|     // CHECK-PPC64:   %[[x_shl:.*]]   = shl i8 %[[x_and]], 7
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|     // CHECK-PPC64:   %[[old_and:.*]] = and i8 %[[old]], 127
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|     // CHECK-PPC64:   %[[new:.*]]     = or i8 %[[old_and]], %[[x_shl]]
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|     // CHECK-PPC64:                     store i8 %[[new]], i8* %[[ptr]]
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|     s->b = x;
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|   }
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| }
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| 
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| namespace N2 {
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|   // Do widen loads and stores to bitfields when those bitfields have padding
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|   // within the struct following them.
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|   struct S {
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|     unsigned b : 24;
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|     void *p;
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|   };
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|   unsigned read(S* s) {
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|     // CHECK-X86-64: define i32 @_ZN2N24read
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|     // CHECK-X86-64:   %[[ptr:.*]] = bitcast %{{.*}}* %{{.*}} to i32*
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|     // CHECK-X86-64:   %[[val:.*]] = load i32* %[[ptr]]
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|     // CHECK-X86-64:   %[[and:.*]] = and i32 %[[val]], 16777215
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|     // CHECK-X86-64:                 ret i32 %[[and]]
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|     // CHECK-PPC64: define zeroext i32 @_ZN2N24read
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|     // CHECK-PPC64:   %[[ptr:.*]] = bitcast %{{.*}}* %{{.*}} to i32*
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|     // CHECK-PPC64:   %[[val:.*]] = load i32* %[[ptr]]
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|     // CHECK-PPC64:   %[[shr:.*]] = lshr i32 %[[val]], 8
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|     // CHECK-PPC64:                 ret i32 %[[shr]]
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|     return s->b;
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|   }
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|   void write(S* s, unsigned x) {
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|     // CHECK-X86-64: define void @_ZN2N25write
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|     // CHECK-X86-64:   %[[ptr:.*]]     = bitcast %{{.*}}* %{{.*}} to i32*
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|     // CHECK-X86-64:   %[[old:.*]]     = load i32* %[[ptr]]
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|     // CHECK-X86-64:   %[[x_and:.*]]   = and i32 %{{.*}}, 16777215
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|     // CHECK-X86-64:   %[[old_and:.*]] = and i32 %[[old]], -16777216
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|     // CHECK-X86-64:   %[[new:.*]]     = or i32 %[[old_and]], %[[x_and]]
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|     // CHECK-X86-64:                     store i32 %[[new]], i32* %[[ptr]]
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|     // CHECK-PPC64: define void @_ZN2N25write
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|     // CHECK-PPC64:   %[[ptr:.*]]     = bitcast %{{.*}}* %{{.*}} to i32*
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|     // CHECK-PPC64:   %[[old:.*]]     = load i32* %[[ptr]]
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|     // CHECK-PPC64:   %[[x_and:.*]]   = and i32 %{{.*}}, 16777215
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|     // CHECK-PPC64:   %[[x_shl:.*]]   = shl i32 %[[x_and]], 8
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|     // CHECK-PPC64:   %[[old_and:.*]] = and i32 %[[old]], 255
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|     // CHECK-PPC64:   %[[new:.*]]     = or i32 %[[old_and]], %[[x_shl]]
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|     // CHECK-PPC64:                     store i32 %[[new]], i32* %[[ptr]]
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|     s->b = x;
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|   }
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| }
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| 
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| namespace N3 {
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|   // Do widen loads and stores to bitfields through the trailing padding at the
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|   // end of a struct.
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|   struct S {
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|     unsigned b : 24;
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|   };
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|   unsigned read(S* s) {
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|     // CHECK-X86-64: define i32 @_ZN2N34read
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|     // CHECK-X86-64:   %[[ptr:.*]] = bitcast %{{.*}}* %{{.*}} to i32*
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|     // CHECK-X86-64:   %[[val:.*]] = load i32* %[[ptr]]
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|     // CHECK-X86-64:   %[[and:.*]] = and i32 %[[val]], 16777215
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|     // CHECK-X86-64:                 ret i32 %[[and]]
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|     // CHECK-PPC64: define zeroext i32 @_ZN2N34read
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|     // CHECK-PPC64:   %[[ptr:.*]] = bitcast %{{.*}}* %{{.*}} to i32*
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|     // CHECK-PPC64:   %[[val:.*]] = load i32* %[[ptr]]
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|     // CHECK-PPC64:   %[[shr:.*]] = lshr i32 %[[val]], 8
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|     // CHECK-PPC64:                 ret i32 %[[shr]]
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|     return s->b;
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|   }
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|   void write(S* s, unsigned x) {
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|     // CHECK-X86-64: define void @_ZN2N35write
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|     // CHECK-X86-64:   %[[ptr:.*]]     = bitcast %{{.*}}* %{{.*}} to i32*
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|     // CHECK-X86-64:   %[[old:.*]]     = load i32* %[[ptr]]
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|     // CHECK-X86-64:   %[[x_and:.*]]   = and i32 %{{.*}}, 16777215
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|     // CHECK-X86-64:   %[[old_and:.*]] = and i32 %[[old]], -16777216
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|     // CHECK-X86-64:   %[[new:.*]]     = or i32 %[[old_and]], %[[x_and]]
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|     // CHECK-X86-64:                     store i32 %[[new]], i32* %[[ptr]]
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|     // CHECK-PPC64: define void @_ZN2N35write
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|     // CHECK-PPC64:   %[[ptr:.*]]     = bitcast %{{.*}}* %{{.*}} to i32*
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|     // CHECK-PPC64:   %[[old:.*]]     = load i32* %[[ptr]]
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|     // CHECK-PPC64:   %[[x_and:.*]]   = and i32 %{{.*}}, 16777215
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|     // CHECK-PPC64:   %[[x_shl:.*]]   = shl i32 %[[x_and]], 8
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|     // CHECK-PPC64:   %[[old_and:.*]] = and i32 %[[old]], 255
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|     // CHECK-PPC64:   %[[new:.*]]     = or i32 %[[old_and]], %[[x_shl]]
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|     // CHECK-PPC64:                     store i32 %[[new]], i32* %[[ptr]]
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|     s->b = x;
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|   }
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| }
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| 
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| namespace N4 {
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|   // Do NOT widen loads and stores to bitfields into padding at the end of
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|   // a class which might end up with members inside of it when inside a derived
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|   // class.
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|   struct Base {
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|     virtual ~Base() {}
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| 
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|     unsigned b : 24;
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|   };
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|   // Imagine some other translation unit introduces:
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| #if 0
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|   struct Derived : public Base {
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|     char c;
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|   };
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| #endif
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|   unsigned read(Base* s) {
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|     // FIXME: We should widen this load as long as the function isn't being
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|     // instrumented by thread-sanitizer.
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|     //
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|     // CHECK-X86-64: define i32 @_ZN2N44read
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|     // CHECK-X86-64:   %[[gep:.*]] = getelementptr inbounds {{.*}}* %{{.*}}, i32 0, i32 1
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|     // CHECK-X86-64:   %[[ptr:.*]] = bitcast [3 x i8]* %[[gep]] to i24*
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|     // CHECK-X86-64:   %[[val:.*]] = load i24* %[[ptr]]
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|     // CHECK-X86-64:   %[[ext:.*]] = zext i24 %[[val]] to i32
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|     // CHECK-X86-64:                 ret i32 %[[ext]]
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|     // CHECK-PPC64: define zeroext i32 @_ZN2N44read
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|     // CHECK-PPC64:   %[[gep:.*]] = getelementptr inbounds {{.*}}* %{{.*}}, i32 0, i32 1
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|     // CHECK-PPC64:   %[[ptr:.*]] = bitcast [3 x i8]* %[[gep]] to i24*
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|     // CHECK-PPC64:   %[[val:.*]] = load i24* %[[ptr]]
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|     // CHECK-PPC64:   %[[ext:.*]] = zext i24 %[[val]] to i32
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|     // CHECK-PPC64:                 ret i32 %[[ext]]
 | |
|     return s->b;
 | |
|   }
 | |
|   void write(Base* s, unsigned x) {
 | |
|     // CHECK-X86-64: define void @_ZN2N45write
 | |
|     // CHECK-X86-64:   %[[gep:.*]] = getelementptr inbounds {{.*}}* %{{.*}}, i32 0, i32 1
 | |
|     // CHECK-X86-64:   %[[ptr:.*]] = bitcast [3 x i8]* %[[gep]] to i24*
 | |
|     // CHECK-X86-64:   %[[new:.*]] = trunc i32 %{{.*}} to i24
 | |
|     // CHECK-X86-64:                 store i24 %[[new]], i24* %[[ptr]]
 | |
|     // CHECK-PPC64: define void @_ZN2N45write
 | |
|     // CHECK-PPC64:   %[[gep:.*]] = getelementptr inbounds {{.*}}* %{{.*}}, i32 0, i32 1
 | |
|     // CHECK-PPC64:   %[[ptr:.*]] = bitcast [3 x i8]* %[[gep]] to i24*
 | |
|     // CHECK-PPC64:   %[[new:.*]] = trunc i32 %{{.*}} to i24
 | |
|     // CHECK-PPC64:                 store i24 %[[new]], i24* %[[ptr]]
 | |
|     s->b = x;
 | |
|   }
 | |
| }
 | |
| 
 | |
| namespace N5 {
 | |
|   // Widen through padding at the end of a struct even if that struct
 | |
|   // participates in a union with another struct which has a separate field in
 | |
|   // that location. The reasoning is that if the operation is storing to that
 | |
|   // member of the union, it must be the active member, and thus we can write
 | |
|   // through the padding. If it is a load, it might be a load of a common
 | |
|   // prefix through a non-active member, but in such a case the extra bits
 | |
|   // loaded are masked off anyways.
 | |
|   union U {
 | |
|     struct X { unsigned b : 24; char c; } x;
 | |
|     struct Y { unsigned b : 24; } y;
 | |
|   };
 | |
|   unsigned read(U* u) {
 | |
|     // CHECK-X86-64: define i32 @_ZN2N54read
 | |
|     // CHECK-X86-64:   %[[ptr:.*]] = bitcast %{{.*}}* %{{.*}} to i32*
 | |
|     // CHECK-X86-64:   %[[val:.*]] = load i32* %[[ptr]]
 | |
|     // CHECK-X86-64:   %[[and:.*]] = and i32 %[[val]], 16777215
 | |
|     // CHECK-X86-64:                 ret i32 %[[and]]
 | |
|     // CHECK-PPC64: define zeroext i32 @_ZN2N54read
 | |
|     // CHECK-PPC64:   %[[ptr:.*]] = bitcast %{{.*}}* %{{.*}} to i32*
 | |
|     // CHECK-PPC64:   %[[val:.*]] = load i32* %[[ptr]]
 | |
|     // CHECK-PPC64:   %[[shr:.*]] = lshr i32 %[[val]], 8
 | |
|     // CHECK-PPC64:                 ret i32 %[[shr]]
 | |
|     return u->y.b;
 | |
|   }
 | |
|   void write(U* u, unsigned x) {
 | |
|     // CHECK-X86-64: define void @_ZN2N55write
 | |
|     // CHECK-X86-64:   %[[ptr:.*]]     = bitcast %{{.*}}* %{{.*}} to i32*
 | |
|     // CHECK-X86-64:   %[[old:.*]]     = load i32* %[[ptr]]
 | |
|     // CHECK-X86-64:   %[[x_and:.*]]   = and i32 %{{.*}}, 16777215
 | |
|     // CHECK-X86-64:   %[[old_and:.*]] = and i32 %[[old]], -16777216
 | |
|     // CHECK-X86-64:   %[[new:.*]]     = or i32 %[[old_and]], %[[x_and]]
 | |
|     // CHECK-X86-64:                     store i32 %[[new]], i32* %[[ptr]]
 | |
|     // CHECK-PPC64: define void @_ZN2N55write
 | |
|     // CHECK-PPC64:   %[[ptr:.*]]     = bitcast %{{.*}}* %{{.*}} to i32*
 | |
|     // CHECK-PPC64:   %[[old:.*]]     = load i32* %[[ptr]]
 | |
|     // CHECK-PPC64:   %[[x_and:.*]]   = and i32 %{{.*}}, 16777215
 | |
|     // CHECK-PPC64:   %[[x_shl:.*]]   = shl i32 %[[x_and]], 8
 | |
|     // CHECK-PPC64:   %[[old_and:.*]] = and i32 %[[old]], 255
 | |
|     // CHECK-PPC64:   %[[new:.*]]     = or i32 %[[old_and]], %[[x_shl]]
 | |
|     // CHECK-PPC64:                     store i32 %[[new]], i32* %[[ptr]]
 | |
|     u->y.b = x;
 | |
|   }
 | |
| }
 | |
| 
 | |
| namespace N6 {
 | |
|   // Zero-length bitfields partition the memory locations of bitfields for the
 | |
|   // purposes of the memory model. That means stores must not span zero-length
 | |
|   // bitfields and loads may only span them when we are not instrumenting with
 | |
|   // thread sanitizer.
 | |
|   // FIXME: We currently don't widen loads even without thread sanitizer, even
 | |
|   // though we could.
 | |
|   struct S {
 | |
|     unsigned b1 : 24;
 | |
|     unsigned char : 0;
 | |
|     unsigned char b2 : 8;
 | |
|   };
 | |
|   unsigned read(S* s) {
 | |
|     // CHECK-X86-64: define i32 @_ZN2N64read
 | |
|     // CHECK-X86-64:   %[[ptr1:.*]] = bitcast {{.*}}* %{{.*}} to i24*
 | |
|     // CHECK-X86-64:   %[[val1:.*]] = load i24* %[[ptr1]]
 | |
|     // CHECK-X86-64:   %[[ext1:.*]] = zext i24 %[[val1]] to i32
 | |
|     // CHECK-X86-64:   %[[ptr2:.*]] = getelementptr inbounds {{.*}}* %{{.*}}, i32 0, i32 1
 | |
|     // CHECK-X86-64:   %[[val2:.*]] = load i8* %[[ptr2]]
 | |
|     // CHECK-X86-64:   %[[ext2:.*]] = zext i8 %[[val2]] to i32
 | |
|     // CHECK-X86-64:   %[[add:.*]]  = add nsw i32 %[[ext1]], %[[ext2]]
 | |
|     // CHECK-X86-64:                  ret i32 %[[add]]
 | |
|     // CHECK-PPC64: define zeroext i32 @_ZN2N64read
 | |
|     // CHECK-PPC64:   %[[ptr1:.*]] = bitcast {{.*}}* %{{.*}} to i24*
 | |
|     // CHECK-PPC64:   %[[val1:.*]] = load i24* %[[ptr1]]
 | |
|     // CHECK-PPC64:   %[[ext1:.*]] = zext i24 %[[val1]] to i32
 | |
|     // CHECK-PPC64:   %[[ptr2:.*]] = getelementptr inbounds {{.*}}* %{{.*}}, i32 0, i32 1
 | |
|     // CHECK-PPC64:   %[[val2:.*]] = load i8* %[[ptr2]]
 | |
|     // CHECK-PPC64:   %[[ext2:.*]] = zext i8 %[[val2]] to i32
 | |
|     // CHECK-PPC64:   %[[add:.*]]  = add nsw i32 %[[ext1]], %[[ext2]]
 | |
|     // CHECK-PPC64:                  ret i32 %[[add]]
 | |
|     return s->b1 + s->b2;
 | |
|   }
 | |
|   void write(S* s, unsigned x) {
 | |
|     // CHECK-X86-64: define void @_ZN2N65write
 | |
|     // CHECK-X86-64:   %[[ptr1:.*]] = bitcast {{.*}}* %{{.*}} to i24*
 | |
|     // CHECK-X86-64:   %[[new1:.*]] = trunc i32 %{{.*}} to i24
 | |
|     // CHECK-X86-64:                  store i24 %[[new1]], i24* %[[ptr1]]
 | |
|     // CHECK-X86-64:   %[[new2:.*]] = trunc i32 %{{.*}} to i8
 | |
|     // CHECK-X86-64:   %[[ptr2:.*]] = getelementptr inbounds {{.*}}* %{{.*}}, i32 0, i32 1
 | |
|     // CHECK-X86-64:                  store i8 %[[new2]], i8* %[[ptr2]]
 | |
|     // CHECK-PPC64: define void @_ZN2N65write
 | |
|     // CHECK-PPC64:   %[[ptr1:.*]] = bitcast {{.*}}* %{{.*}} to i24*
 | |
|     // CHECK-PPC64:   %[[new1:.*]] = trunc i32 %{{.*}} to i24
 | |
|     // CHECK-PPC64:                  store i24 %[[new1]], i24* %[[ptr1]]
 | |
|     // CHECK-PPC64:   %[[new2:.*]] = trunc i32 %{{.*}} to i8
 | |
|     // CHECK-PPC64:   %[[ptr2:.*]] = getelementptr inbounds {{.*}}* %{{.*}}, i32 0, i32 1
 | |
|     // CHECK-PPC64:                  store i8 %[[new2]], i8* %[[ptr2]]
 | |
|     s->b1 = x;
 | |
|     s->b2 = x;
 | |
|   }
 | |
| }
 |